Global Seroprevalence Research Articles

Global epidemiology, genotype distribution and coinfection rate of Human Aichi virus: A systematic review

BackgroundAcute gastroenteritis is a major health concern for all age groups and accounts for more than 2.5 million deaths annually in children under five years old. Human Aichi virus causes acute gastroenteritis and is associated with foodborne outbreaks. Little is known about its pathogenicity, evolution, and geographical distribution. ObjectiveThis study aimed to describe the global seroprevalence of AiV-1 and its genotype distribution, track outbreaks, and estimate co-infection rates with other viral gastroenteritis. MethodsA comprehensive systematic search of the epidemiological aspects of AiV-1 was conducted using peer-reviewed English original articles indexed in several scientific database libraries since its first detection in Japan until October 2022. A total of 55 published studies were included in the final analysis based on the inclusion criteria. ResultThe global prevalence of AiV-1 was 1.45 %. To date, nine AiV-1 outbreaks were reported following the first oyster-associated outbreak in Japan between 1987 and 1991. AiV-1 genotype A has a worldwide distribution, whereas genotypes B and C have a pattern of geo-localization. The gradual and significant increase of AiV-1 seroprevalence with age was reported in all studies. The most predominant viruses causing viral coinfection among AiV-1-infected patients were Norovirus (36.55 %), Rotavirus (18.91 %), and Sapovirus (15.13 %). Coinfections with Norovirus (p-value 0.003), Rotavirus (p = 0.007), and Human Astrovirus (p = 0.032) were significantly correlated with AiV-1 coinfection. ConclusionThis was the first comprehensive systematic review of AiV-1. Although AiV-1 has a low global prevalence, it can be considered a health concern due to its association with childhood gastroenteritis.

Global seroprevalence and factors associated with seropositivity for feline immunodeficiency virus (FIV) in cats: A systematic review and meta-analysis

The feline immunodeficiency virus (FIV) is a retrovirus of the Lentivirus genus, distributed worldwide, that causes persistent infection with a significant impact on the cats’ health. Due to the importance of this infection in feline medicine, this pioneering study aimed to obtain an integrated estimate of the global seroprevalence of FIV in cats and to characterize the factors associated with this infection. Four electronic databases were screened for observational studies with FIV seroprevalence in cats published globally for this systematic review and meta-analysis. The initial search method returned 873 studies, of which 113 met all predefined criteria and were therefore included in this review. Meta-analysis with general data was performed, and a combined global seropositivity of 9.43 % (95 % CI: 8.24 % – 10.78 %) was found. Seropositivity was 14.34 % (95 % CI = 10.92 % – 18.61 %) in Asia, 11.90 % (95 % CI = 9.82 % – 14.34 %) in Oceania, 10.90 % (95 % CI = 5.71 % – 19.82 %) in Central America, 9.43 % (95 % CI = 6.95 % – 12.66 %) in South America, 9 % (95 % CI = 0 – 80 %) in Africa, 8.98 % (95 % CI = 7.31 % – 10.98 %) in Europe, and 5.93 % (95 % CI = 4.33 % – 8.07 %) in North America. Meta-analysis of factors associated with seropositivity demonstrated that FIV seroprevalence was higher in male (Prevalence ratio [PR] = 2.53, 95 % CI = 2.16 – 2.95), adult (PR = 2.83, 95 % CI = 2.24 – 3.56), unowned status (PR = 1.47, 95 % CI = 1.07 – 2.03), sick status (PR = 2.46, 95 % CI = 1.97 – 3.06), and cats with outdoor access (PR = 4.38, 95 % CI = 2.26 – 8.47). The results demonstrated that FIV is globally distributed and has a high seroprevalence in some geographical areas. Information compiled from this research is relevant to understanding the worldwide epidemiology of FIV. It presents the potential to contribute to the planning of strategies focused on controlling and reducing cases in cat populations.

Global epidemiology, natural history, maternal-to-child transmission, and treatment with DAA of pregnant women with HCV: a systematic review and meta-analysis

Pregnant women with hepatitis C virus (HCV) infection represent a special population in which treatment access remains limited despite its increasing prevalence. A reliable estimate of the burden and clinical outcomes of pregnant women with HCV infection is crucial for HCV elimination. We aimed to determine the prevalence, maternal-to-child transmission (MTCT), maternal and fetal complication rates, and direct acting antivirals (DAA) treatment outcomes of chronic HCV infection in pregnant women. We searched PubMed, EMBASE, Scopus, Web of Science from inception until March 1, 2024, for studies reporting on the prevalence, MTCT, complications of HCV infection, and treatment outcomes of DAA in pregnant women. Study quality was assessed using the Newcastle-Ottawa Scale. We performed subgroup analysis based on 9 variables to explore the source of heterogeneity in HCV prevalence. The PROSPERO registration number is CRD42024500023. From a total of 311,905,738 pregnant women from 333 studies, the pooled global seroprevalence of HCV in pregnant women was 2.6% (95% CI: 2.0-3.2, I 2=100%) which increased in patients with intravenous drug use and HIV. Majority of the HCV cases in pregnant women (75%) are diagnosed through universal screening. The pooled MTCT rate was 9.0% (95% CI: 6.6-11.7, I 2=79%), which was higher with HIV co-infection (OR: 3.1, 95% CI: 2.1-4.6, I 2=10%), but was not influenced by the mode of delivery or breastfeeding. Pregnant women with HCV infection had more maternal complications, including intrahepatic cholestasis, preterm delivery, and antepartum hemorrhage. Neonates of mothers with HCV had higher odds of being small for gestational age. The pooled rate of sustained virologic response (SVR12) among the 74 women treated with DAA during pregnancy was 98.4%, with no serious adverse events reported. HCV prevalence in pregnant women varies by geographic region and patient population, while MTCT occurs in almost one in ten viremic mothers. The incidence of both maternal and neonatal complications is significantly higher in patients with HCV infection. Limited data suggest that DAA are safe in pregnant women with HCV infection. None.

Serosurvey of canine leishmaniasis in five departments near an identified human clinical case in Marseille (France)

Leishmania infantum is a protozoan parasite of the family Trypanosomatidae, transmitted by the bite of phlebotomine sand flies (Diptera: Psychodidae). It is responsible for human and canine leishmaniasis in countries bordering the Mediterranean basin. Here we describe a clinical case of human cutaneous leishmaniasis in a 76-year-old female patient living in Marseille. Upon interrogation, the patient had no history of recent travel or contact with animals. The study involved clinical, serological, and molecular investigation of the occurrence of Leishmania infection in 718 dogs from five departments within a 130 km radius perimeter around Marseille. Five dogs showed signs of moderate leishmaniasis. Additionally, the serological survey of dogs revealed a global seroprevalence of 5.1%, with a significantly different prevalence in the Vaucluse department. Molecular analysis and phylogenetic studies highlighted the close relatedness of Leishmania strains between human and canine hosts with 99.6% of identity, indicating local transmission. The findings underscore the importance of serological surveillance in dogs and human. In a One Health approach, it is necessary to continue investigating Leishmania infection in all potential reservoirs, especially for zoonotic L. infantum in wildlife (red foxes, leporids, rodents, etc.) but also in dogs, cats, and equids.

Global and regional seroprevalence, incidence, mortality of, and risk factors for scrub typhus: A systematic review and meta-analysis

ObjectivesScrub typhus is underdiagnosed and underreported but emerging as a global public health problem. We aimed to provide the first comprehensive review on the seroprevalence, incidence, mortality of and risk factors for scrub typhus. MethodsWe searched PubMed, Scopus, Web of Science, China National Knowledge Infrastructure and other databases. Trended incidence and median mortality were calculated and pooled seroprevalence and risk factors for scrub typhus were evaluated using the random-effects meta-analysis. ResultsWe included 663 articles from 29 countries/regions. The pooled seroprevalence was 10.73% (95%CI 9.47-12.13%) among healthy individuals and 22.58% (95%CI: 20.55%-24.76%) among febrile patients. Mainland China reported the highest number of cases and South Korea and Thailand had the highest incidence rates. Median mortalities were 5.00% (range: 0.00-56.00%) among hospital inpatients, 6.70% (range: 0.00-33.33%) among patients without specified admission status and 2.17% (range: 0.00-22.22%) among outpatients. The significant risk factors included agricultural work, specific vegetation exposure, other outdoor activities, risky personal health habits, and proximity to rodents, livestock, or poultry. ConclusionsOur comprehensive review elucidates the significant yet variable burden of scrub typhus across different regions, underscoring its emergence as a critical public health concern globally.

Global seroprevalence of neutralizing antibodies against adeno-associated virus serotypes used for human gene therapies

Adeno-associated virus (AAV) vectors are promising gene therapy candidates, but pre-existing anti-AAV neutralizing antibodies (NAbs) pose a significant challenge to successful gene delivery. Knowledge of NAb seroprevalence remains limited and inconsistent. We measured activity of NAbs against six clinically relevant AAV serotypes across 10 countries in adults (n= 502) and children (n= 50) using a highly sensitive transduction inhibition assay. NAb prevalence was generally highest for AAV1 and lowest for AAV5. There was considerable variability across countriesand geographical regions. NAb prevalence increased with age and was higher in females, participants of Asian ethnicity, and participants in cancer trials. Co-prevalence was most frequently observed between AAV1 and AAV6 and less frequently between AAV5 and other AAVs. Machine learning analyses revealed a unique clustering of AAVs that differed from previous phylogenetic classifications. These results offer insights into the biological relationships between the immunogenicity of AAVs in humans beyond that observed previously using standard clades, which are based on linear capsid sequences. Our findings may inform improved vector design and facilitate the development of AAV vector-mediated clinical gene therapies.

Serology survey of Ascaris suum and Trichinella spiralis in rural pigs in Southwestern Mexico.

Parasitic diseases of pigs are a public and veterinary health problem. Helminths influence pork production, whereas backyard pigs can transmit these parasites. This work aimed to investigate the prevalence of antibodies against Ascaris suum and Trichinella spiralis in backyard pigs from Jamiltepec, Region de la Costa, Oaxaca, in Southwestern Mexico. Six hundred sixty-four serum samples were obtained from backyard pigs from 23 rural villages distributed in 5 municipalities; samples were taken in a non-probabilistic manner with the owner's consent. The presence of serum antibodies against a total extract of A. suum adult worm was determined by ELISA. In contrast, antibodies to the excretion-secretion products of the T. spiralis muscle larva were determined by Western blot. The global seroprevalence for A. suum was 5.12% and 2.41% for T. spiralis; however, antibodies were only found in 8 villages and distributed in 3 municipalities. The highest frequency of positivity for Ascaris was found in the municipality of Santa Catarina Mechoacán (13.01%), whereas, in Santa María Huazalotitlán, the highest frequency of positivity for Trichinella was found (5.75%). In San Andrés, frequencies were 7.23% and 4.82%, respectively. No statistical differences were observed between populations. Our data suggest that helminth transmission is restricted by locality. However, further studies must be conducted to understand the factors limiting this transmission to promote pork meat production in parasite-free zones.

Global and regional seroprevalence of coxiellosis in small ruminants: A systematic review and meta-analysis.

Coxiellosis is a neglected zoonosis for occupationally exposed people in many parts of the world. Sheep and goats are two important small ruminants that act as reservoirs for human contamination; however, there is a lack of comprehensive data on the epidemiological aspects of coxiellosis in sheep and goats at regional and global levels. The aim of this study was to systematically review the available articles on seroprevalence of coxiellosis in sheep and goats and estimate the overall seroprevalence in different regions. A systematic search strategy was performed in five electronic repositories for articles published until December 2021. Relevant data were extracted from the selected articles based on the inclusion criteria. A random effect meta-analysis model was used to analyse the data. Results are presented as the prevalence of seropositivity as a percentage and 95% confidence intervals. The global pooled seroprevalence of coxiellosis in sheep was 17.38% (95% confidence interval [CI]: 15.59%-19.17%). Overall, the regional level pooled prevalence estimates in sheep ranged from 15.04% (95% CI: 7.68%-22.40%) to 19.14% (95% CI: 15.51%-22.77%), depending on region. The global pooled seroprevalence of coxiellosis in goats was 22.60% (95% CI: 19.54%-25.66%). Overall, the regional level pooled prevalence estimates in goats ranged from 6.33% (95% CI: 2.96%-9.71%) to 55.13% (95% CI: 49.61%-60.65%), depending on the region. The prevalence estimates also varied significantly in both sheep and goats depending on age, sex, and rearing systems of the animals (p<0.001). Seroprevalence of coxiellosis in both sheep and goats is considerable. Routine monitoring of the sheep and goat populations is needed to prevent spillover infection in other livestock and humans.

Impact of herd mobility on brucellosis seroprevalence and spread risk resulting from cross-border transhumance.

Cross-border livestock mobility through transhumance is mainly practiced in West African countries for seasonal access to resources and market. Cross-border herds are involved in the dynamic of transboundary animal diseases among them brucellosis taken as model. Brucellosis is a zoonotic disease causing abortion. This study explores the seroprevalence of brucellosis according to mobility and infection spread between Mali and Côte d'Ivoire in the context of seasonal cross-border transhumance. From February to April 2021, a transversal serological survey of brucellosis was conducted on 521 cattle from 111 transhumant herds and 283 cattle from 59 sedentary herds, all from Mali. The global individual seroprevalence for Brucella spp. in transhumant and sedentary cattle from Mali was 8.2% (95% CI=6.0-10.5). At herd level, seroprevalence was 21.2% with a significant variation between transhumant (11.7%) and sedentary (39.0%) herds. For herds in transhumance, cattle seropositivity was associated with a previous infection suspected by herdsmen odds ratio (OR=4.4; 95% CI=1.1-18.1) and unknown abortion aetiology (OR=4.3; 95% CI=1.0-17.3). The departure region (coming from Sikasso) and previous brucellosis infection or unexplained abortion could be used to predict Brucella infection in transhumant herds with a probability of around 60%. The risk of brucellosis introduction in host regions was high despite the individual animal seroprevalence of 3.6% and a low sale rate in transhumant cattle. The findings suggest that testing transhumant during border control and survey of cattle markets and sales could improve risk control of the spread of disease at regional scale.

Seroprevalence of cytomegalovirus (CMV) among pregnant women at a tertiary facility in southern Nigeria

Background: Cytomegalovirus (CMV) also called human cytomegalovirus (HCMV) or human herpesvirus-5 (HHV-5) is an encapsulated double-stranded deoxyribonucleic acid (DNA) virus. It is an opportunistic virus which often remains latent and only become symptomatic in immune-suppressed individuals such as pregnant women, HIV/AIDS patients and other immune weakening disease conditions. It is also estimated to have an 86% global sero-prevalence among reproductive women. Objectives: To determine the sero-prevalence of CMV infection, investigate the relationship between risk factors and CMV infection and to determine the relationship between obstetric characteristics and CMV infections among pregnant women. Method: A cross-sectional study among a cross-section of pregnant women receiving ante-natal care in the University of Port Harcourt Teaching Hospital from August 2022 to December 2022. A structured pro forma data sheet was used as interviewer-administered questionnaire by medical personnel to collect data from the study participants. 5ml of blood was collected from each participant and assessed for the presence of anti-CMV IgG using commercial Enzyme-linked Immunosorbent Assay (ELISA). The data were analyzed using Statistical Package for Social Sciences (SPSS) version 25. Descriptive statistics (mean, median, frequency percentage and standard deviation), Chi-square test and Fischer’s exact test were used appropriately. Results: Out of 101 respondents, only 24 (24%) were positive for CMV IgG, while 77 (76%) were negative. About 50% of the women were in their 3rd decade of life, while (3) were in the 4th decade of life. All the respondents were married and were Christians. Three quarters of the women [75(74.3%)] had tertiary education, 20 (19.8%) had secondary education, while 6 (5.9%) were Postgraduate students. Based on income, women with income &lt; #50,000 (53.5%) were the most common. The relationship between demographic factors such as age, religion, income, educational level, employment status, marital status and CMV results were statistically insignificant. The relationship between obstetric characteristics and CMV results were not statistically significant, while risk factors for CMV and presence of CMV infection were not statistically significant as well. Conclusion: The 24% sero-prevalence for CMV at University of Port Harcourt Teaching Hospital was quite low; however it can be reduced to the barest minimum, by encouraging intensive awareness campaigns about the virus and providing free serum testing to all categories of the population, since CMV affects all ages.

High pre-Delta and early-Omicron SARS-CoV-2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo).

Studies on the impact of the COVID-19 pandemic in sub-Saharan Africa have yielded varying results, although authors universally agree the real burden surpasses reported cases. The primary objective of this study was to determine SARS-CoV-2 seroprevalence among patients attending Monkole Hospital in Kinshasa (D.R. Congo). The secondary objective was to evaluate the analytic performance of two chemiluminescence platforms: Elecsys® (Roche) and VirClia® (Vircell) on dried blood spot samples (DBS). The study population (N = 373) was recruited in two stages: a mid-2021 blood donor cohort (15.5% women) and a mid-2022 women cohort. Crude global seroprevalence was 61% (53.9%-67.8%) pre-Delta in 2021 and 90.2% (84.7%-94.2%) post-Omicron in 2022. Anti-spike (S) antibody levels significantly increased from 53.1 (31.8-131.3) U/mL in 2021 to 436.5 (219.3-950.5) U/mL in 2022 and were significantly higher above 45 years old in the 2022 population. Both platforms showed good analytic performance on DBS samples: sensitivity was 96.8% for IgG (antiN/S) (93.9%-98.5%) and 96.0% (93.0%-98.0%) for anti-S quantification. These results provide additional support for the notion that exposure to SARS-CoV-2 is more widespread than indicated by case-based surveillance and will be able to guide the pandemic response and strategy moving forward. Likewise, this study contributes evidence to the reliability of DBS as a tool for serological testing and diagnosis in resource-limited settings.

Human Trypanosoma cruzi infection in the Argentinean Chaco: risk factors and identification of households with infected children for treatment

BackgroundChagas disease is a neglected tropical disease (NTD). Cost-effective strategies for large-scale implementation of diagnosis and etiological treatment are urgently needed to comply with NTD control goals. We determined the seroprevalence of Trypanosoma cruzi infection and associated risk factors in a well-defined rural population of Pampa del Indio municipality including creole and indigenous (Qom) households and developed two indices to identify houses harboring infected children.MethodsWe serodiagnosed and administered a questionnaire to 1337 residents (48.2% of the listed population) in two sections of the municipality (named Areas II and IV) 6–9 years after deploying sustained vector control interventions. Multiple logistic regression models were used to evaluate the relationship between human infection and a priori selected predictors. Two risk indices were constructed based on environmental and serostatus variables, and we used spatial analysis to test whether households harboring T. cruzi-seropositive children were randomly distributed.ResultsThe global seroprevalence of T. cruzi infection was 24.8%. Human infection was positively and significantly associated with exposure time to triatomines, the household number of seropositive co-inhabitants, maternal seropositivity for T. cruzi, recent residence at the current house and the presence of suitable walls for triatomine colonization in the domicile. The pre-intervention mean annual force of infection (FOI) was 1.23 per 100 person-years. Creoles from Area IV exhibited the highest seroprevalence and FOI; Qom people from both areas displayed intermediate ones and creoles from Area II the lowest. Three hotspots of infected children were spatially associated with hotspots of triatomine abundance at baseline and persistent house infestation. No child born after vector control interventions was T. cruzi seropositive except for one putative transplacental case. Two simple risk indices (based on self-reported inhabiting an infested house and suitable walls for triatomines or maternal serostatus) identified 97.3–98.6% of the households with at least one T. cruzi-seropositive child.ConclusionsWe showed strong heterogeneity in the seroprevalence of T. cruzi infection within and between ethnic groups inhabiting neighboring rural areas. Developed indices can be used for household risk stratification and to improve access of rural residents to serodiagnosis and treatment and may be easily transferred to primary healthcare personnel.Graphical

Hepatitis C infection seroprevalence in pregnant women worldwide: a systematic review and meta-analysis

Monitoring progress towards the WHO global target to eliminate hepatitis C virus (HCV) infection by 2030, entails reliable prevalence estimates for HCV infection in different populations. Little is known about the global burden of HCV infection in pregnant women. Here, for the first time to our knowledge, we estimated the global and regional seroprevalence of HCV antibody (Ab) and determinants in pregnant women. In this systematic review and meta-analysis study, we searched PubMed/MEDLINE, Web of Science, Embase, Scopus, and SciELO databases for peer-reviewed observational studies between January 1, 2000 and April 1, 2023, without language or geographical restrictions. Pooled global seroprevalence (and 95% confidence interval, CI) were estimated using random-effects meta-analysis and seroprevalences were categorised according to World Health Organization regions and subregions, publishing year, countries' income and human development index (HDI) levels. We used sensitivity analysis to assess the effect of four large sample size studies on pooled global prevalence through the "leave-one-out" method. We also investigated the association of potential risk factors with HCV seropositivity in pregnant women by subgroup and meta-regression analyses. The Protocol was registered in PROSPERO CRD42023423259. We included 192 eligible studies (208 datasets), with data for 148,509,760 pregnant women from 53 countries. The global seroprevalence of HCV Ab in pregnant women was 1.80% (95% CI, 1.72-1.89%) and 3.29% (3.01-3.57%) in overall and sensitivity analyses, respectively. The seroprevalence was highest in the Eastern Mediterranean region (6.21%, 4.39-8.29%) and lowest in the Western Pacific region (0.75%, 0.38-1.22%). Subgroup analysis indicated that the seroprevalence of HCV Ab among pregnant women was significantly higher for those with opioid use disorder (51.94%, 95% CI: 37.32-66.39) and HIV infection (4.34%, 95% CI: 2.21-7.06%) than for the general population of pregnant women (1.08%, 95% CI: 1.02-1.15%), as confirmed by multivariable meta-regression (p<0.001). A significant decreasing trend was observed with increasing human development index levels. Other important risk factors for HCV seropositivity included older age, lower educational levels, poly sexual activity, history of blood transfusion, hospitalization, surgery, abortion and sexual transmitted diseases, having scarification/tattoo or piercing, and testing hepatitis B positive. This meta-analysis showed relatively high burden of exposure to HCV infection (2.2-5.3 million) in pregnant women globally. However, due to substantial heterogeneity between studies, our estimates might be different than the true seroprevalence. Our findings highlighted the need to expand HCV screening for women of reproductive age or during pregnancy, particularly in countries with high prevalence; as well as for more studies that assess safety of existing therapeutic drugs during pregnancy or potentially support development of drugs for pregnant women. There was no funding source for this study.

Population measles seroprevalence: Heterogeneity by birth-year cohort

ObjectiveThis work sought to estimate population measles seroprevalence and heterogeneity in the antibody concentration distribution that could be explained by the birth-year cohort according to the opportunity of viral and vaccine exposure, applied to data from Medellín, Colombia. MethodsPrevalence of IgG antibodies was analyzed for measles based on a population study with a random sample of 2098 individuals from 6 to 64 years of age. Finite mixture models were used to estimate global seroprevalence and that of three birth-year cohorts (I: born up to 1982; II: 1983–1994; III: born since 1995). Multiple linear regression permitted adjusting the concentration of antibodies by cohort, zone, and sex. ResultsGlobally, seronegativity was 6.5% (95% CI 4.9– 8.6), seropositivity of 78.4% (95% CI 75.1–81.4), and equivocal of 15.1% (95% CI 12.5–18.1). Two components were found with skewed normal distribution, which reclassified those equivocal as seropositive. Differences were observed by cohort in the geometric mean of antibodies [Cohort I: 1704.6; II: 562.2; III: 802.1 milli-international units per milliliter (mIU/mL] and seronegativity (Cohort I: 4%; II:13.3%; III: 8.9%). Antibody concentration increased by 1.26 mIU/mL in residents in the rural area, while diminishing in individuals from cohort II (by 3.02 mIU/mL) and cohort III (by 2.14 mIU/mL). ConclusionThe younger cohorts (II and III) had a lower antibody concentration (higher seronegativity), indicating the need to monitor periodically seroprevalence and an eventual reestablishment of the transmission in these groups with higher risk of infection.

Baseline Seroprevalence of SARS-CoV-2 Specific Antibodies in Hot Spot Areas of Great Tunis, up to 3 Months Post Disease Onset in Tunisia.

The extent of the SARS-CoV-2 circulation and the COVID-19 epidemic in Tunisia three months after virus circulation was unknown. The aim of this study was to determine the extent of SARS-CoV-2 infection among household contacts of confirmed COVID-19 cases living in Hot spot areas of Great Tunis, Tunisia by estimating the seroprevalence of antibodies anti SARS-CoV-2 and to identify factors associated to seroprevalence at the first stage of the pandemic in order to guide decision making and to constitute a baseline for further longitudinal analysis of protective immunity to SARS-CoV-2. The National Observatory of New and Emerging Diseases (ONMNE), Ministry of Health Tunisia (MoH), with the support of the Office of the World Health Organization Representative in Tunisia and the WHO Regional Office for the Eastern Mediterranean (EMRO)), conducted a household cross-sectional survey on April 2020 in Great Tunis (Tunis, Ariana, Manouba and Ben Arous). The study was based on the WHO seroepidemiological investigation protocol for SARS-CoV-2 infection. SARS-CoV-2 specific antibodies (IgG and IgM) were qualitatively detected using a lateral immunoassay that detect SARS-CoV-2 nucleocapsid protein and administered by the interviewers. The included subjects were confirmed COVID-19 cases and their households contacts resided in hot spot areas (cumulative incidence rate ≥ 10 cases/100,000 inhabitants) of Great Tunis. Results: In total, 1165 subjects were enrolled: 116 confirmed COVID-19 cases (43 active cases and 73 convalescents cases) and 1049 household contacts resided in 291 households. The median age of participants was 39.0 with 31 years' interquartile range (Min = 8 months; Max = 96 years). The sex ratio (M/F) was 0.98. Twenty-nine per cent of participants resided in Tunis. The global crude seroprevalence among household contacts was 2.5% (26/1049); 95% CI 1.6-3.6%, 4.8%; 95% CI 2.3-8.7% in Ariana governorate and 0.3%; 95% CI 0.01%-1.8% in Manouba governorate. In multivariate analysis, the associated factors independently related to seroprevalence were age ≥25 years (aOR = 5.1; 95% CI 1.2-22.0), history of travel outside Tunisia since January 2020 (aOR = 4.6; 95% CI 1.7-12.9), symptomatic illness in the previous four months (aOR = 3.5; 95% CI 1.4-9.0) and governorate of residence (p = 0.02). The low seroprevalence estimated among household contacts in Great Tunis reflect the effect of public health measures early taken (national lockdown, borders closed, remote work), the respect of non-pharmaceutical interventions and the efficacy of COVID-19 contact-tracing and case management at the first stage of the pandemic in Tunisia.

Global seroprevalence of Toxoplasma gondii infection among patients with mental and neurological disorders: A systematic review and meta-analysis.

Toxoplasmosis is the most widespread zoonotic disease that affects one-third of the world's population, and imposes a major public health problem worldwide. This study aimed to assess the prevalence of toxoplasmosis among patients with neuropsychiatric patients. Electronic databases PubMed, Google Scholar, Web of Science, Research Gate, and Scopus were thoroughly searched from February to March 2022 to identify all relevant studies. The quality of studies was evaluated using the Newcastle-Ottawa quality scale for case-control and cross-sectional studies. Statistical analysis was done using STATA version 12 software. A random effect model was used to compute the global pooled seroprevalence of Toxoplasma gondii infection. Heterogeneity was quantified by using I 2 value. Subgroup analysis was done, and publication bias was assessed using a funnel plot and Egger's test. Of 1250 studies, 49 containing 21,093 participants and conducted in 18 countries were included. The global pooled seroprevalence of T. gondii IgG antibody was 38.27% (95% CI: 32.04-44.9) among neuropsychiatric patients and 25.31% (95% CI: 21.53-29.08) in healthy controls with substantial heterogeneity of 98.3%. The prevalence of T. gondii IgG antibody was higher in males (17.52%) than in females (12.35%) neuropsychiatric patients. The highest pooled prevalence of T. gondii IgG antibody was in Europe (57%) followed by Africa (45.25%) and Asia (43%). Time based analysis showed the highest pooled prevalence of T. gondii IgG antibody in 2012-2016 (41.16%).The global pooled seroprevalence T. gondii IgM antibody among neuropsychiatric patients and healthy controls was 6.78% (95% CI: 4.87-8.69) and 3.13% (95% CI: 2.02-4.24), respectively. The pooled prevalence of chronic and acute T. gondii infection among neuropsychiatric patients was 38.27% and 6.78%, respectively. This showed a high burden of toxoplasmosis among neurological and psychiatric patients and urges routine screening of those patients and providing appropriate treatment. It also indicates the need for different stakeholders to develop targeted prevention and control strategies for T. gondii infection.

Global prevalence of hepatitis B or hepatitis C infection among patients with tuberculosis disease: systematic review and meta-analysis

There is a substantial overlap in the epidemiology of chronic hepatitis B (HBV), hepatitis C (HCV) and tuberculosis (TB) due to overlapping risk factors. Testing for viral hepatitis is not widely recommended for patients with TB. The aim of this systematic review was to evaluate the global prevalence of chronic viral hepatitis infection among patients with TB. MEDLINE, EMBASE, Web of Science, Cochrane Library, African Journals Online, LILACS, and country TB reports were searched for studies published between January 1st, 2011 and June 17th 2021. Random-effects meta-analyses for proportions were conducted to obtain pooled prevalences. The prevalence of chronic HBV/HCV infection among patients with TB was also compared to that in the general population. The protocol was registered on PROSPERO (CRD42021276468). This analysis included 127 studies (83 for both HBV and HCV, 28 for HBV only, and 25 for HCV only) and data from 94,936 patients. The global pooled seroprevalence was 5.8% (95% CI 5.0-6.8) for HBs-antigen and 10.3% (95% CI 8.4-12.3) for HCV-antibodies. Pooled prevalence was highest in the WHO African Region for HBV at 7.8% (95% CI 5.2-10.9) and in the WHO European Region at 17.5% (95% CI 12.2-23.5) for HCV. In studies among TB patients who inject drugs, HCV prevalence was 92.5% (95% CI 80.8-99.0). Pooled HCV-antibody seroprevalence among patients with TB was higher than in the general population in all six WHO regions while HBs-antigen seroprevalence was higher in 3/6 regions. This review highlights the syndemicity of chronic viral hepatitis and TB and suggests that routine testing for hepatitis upon TB diagnosis may be justified. The prevalence of chronic HBV and HCV infections was higher among patients with TB than in the general population. This study was study was funded by the Global Tuberculosis Programme, World Health Organization.

The Global Seroprevalence of Equine Brucellosis: A Systematic Review and Meta-analysis Based on Publications From 1990 to 2022.

Brucellosis, a bacterial infection caused by Brucella spp., is a widespread zoonosis concerning human and animal health. In equines, brucellosis may occur asymptomatically or with clinical signs such as arthritis, bursitis, and tenosynovitis. This study aims to ascertain the overall seroprevalence of equine brucellosis and its related factors, including geographic region, serological detection method, equine's species, gender, age, and body condition. This is because equine brucellosis is a zoonotic infection with significant epidemiological implications. The systematic literature search was conducted from January 1, 1990, to April 1, 2022, in the following electronic databases: Google Scholar, Scopus, Pub Med, Science Direct, Web of Science, Embase, Springer, and ProQuest. Based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) and inclusion criteria, 49 qualified studies were acquired from several countries. Because Egger's test result and the asymmetry in the funnel plot indicated significant publication bias, the meta-analysis model was corrected using the trim-and-fill method. After correction, the pooled seroprevalence of equine brucellosis was 1.92% (95% CI, 0.67-3.79; estimated by the random effect model). Based on meta-regression analysis, the probable heterogeneity factors may be geographic areas (continents and countries). The brucellosis seroprevalence in equines was the lowest in Europe (0%, 95% CI, 0-0.1) and the highest in Asia (10.03%, 95% CI, 8-12.9). The highest overall estimate of seroprevalence of Brucella infection in equines based on a subset of serological tests was made using the serum agglutination test (10.2%, 95% CI, 7.7-13.4). The combined seroprevalence of brucellosis in donkeys (7.3%, 95% CI, 4.9-9.7) was higher than in other equine species. The overall seroprevalence of brucellosis in female equines was significantly higher than in males (OR=1.437; 95% CI, 1.025-2.014); despite this, the overall seroprevalence had no significant difference based on other risk factors such as age and body condition. Understanding the epidemiology of this zoonotic infection in equines is critical for one-health integration. In addition, this study's results may be appropriate for controlling and managing equine brucellosis.

Current landscape in antiviral drug development against herpes simplex virus infections.

Herpes simplex viruses (HSV) are common human pathogens with a combined global seroprevalence of 90% in the adult population. HSV-1 causes orofacial herpes but can cause severe diseases, such as the potentially fatal herpes encephalitis and herpes keratitis, a prevalent cause of infectious blindness. The hallmark of HSV is lifelong latent infections and viral reactivations, leading to recurrent lesions or asymptomatic shedding. HSV-1 and HSV-2 can cause recurrent, painful, and socially limiting genital lesions, which predispose to human immunodeficiency virus infections, and can lead to neonatal herpes infections, a life-threatening condition for the newborn. Despite massive efforts, there is no vaccine against HSV, as both viruses share the capability to evade the antiviral defenses of human and to establish lifelong latency. Recurrent and primary HSV infections are treated with nucleoside analogs, but the treatments do not completely eliminate viral shedding and transmission. Drug-resistant HSV strains can emerge in relation to long-term prophylactic treatment. Such strains are likely to be resistant to other chemotherapies, justifying the development of novel antiviral treatments. The importance of developing new therapies against HSV has been recognized by the World Health Organization. In this review, we discuss the current approaches for developing novel antiviral therapies against HSV, such as small molecule inhibitors, biopharmaceuticals, natural products, gene editing, and oligonucleotide-based therapies. These approaches may have potential in the future to answer the unmet medical need. Furthermore, novel approaches are presented for potential eradication of latent HSV.

Global SARS-CoV-2 seroprevalence from January 2020 to April 2022: A systematic review and meta-analysis of standardized population-based studies.

Our understanding of the global scale of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection remains incomplete: Routine surveillance data underestimate infection and cannot infer on population immunity; there is a predominance of asymptomatic infections, and uneven access to diagnostics. We meta-analyzed SARS-CoV-2 seroprevalence studies, standardized to those described in the World Health Organization's Unity protocol (WHO Unity) for general population seroepidemiological studies, to estimate the extent of population infection and seropositivity to the virus 2 years into the pandemic. We conducted a systematic review and meta-analysis, searching MEDLINE, Embase, Web of Science, preprints, and grey literature for SARS-CoV-2 seroprevalence published between January 1, 2020 and May 20, 2022. The review protocol is registered with PROSPERO (CRD42020183634). We included general population cross-sectional and cohort studies meeting an assay quality threshold (90% sensitivity, 97% specificity; exceptions for humanitarian settings). We excluded studies with an unclear or closed population sample frame. Eligible studies-those aligned with the WHO Unity protocol-were extracted and critically appraised in duplicate, with risk of bias evaluated using a modified Joanna Briggs Institute checklist. We meta-analyzed seroprevalence by country and month, pooling to estimate regional and global seroprevalence over time; compared seroprevalence from infection to confirmed cases to estimate underascertainment; meta-analyzed differences in seroprevalence between demographic subgroups such as age and sex; and identified national factors associated with seroprevalence using meta-regression. We identified 513 full texts reporting 965 distinct seroprevalence studies (41% low- and middle-income countries [LMICs]) sampling 5,346,069 participants between January 2020 and April 2022, including 459 low/moderate risk of bias studies with national/subnational scope in further analysis. By September 2021, global SARS-CoV-2 seroprevalence from infection or vaccination was 59.2%, 95% CI [56.1% to 62.2%]. Overall seroprevalence rose steeply in 2021 due to infection in some regions (e.g., 26.6% [24.6 to 28.8] to 86.7% [84.6% to 88.5%] in Africa in December 2021) and vaccination and infection in others (e.g., 9.6% [8.3% to 11.0%] in June 2020 to 95.9% [92.6% to 97.8%] in December 2021, in European high-income countries [HICs]). After the emergence of Omicron in March 2022, infection-induced seroprevalence rose to 47.9% [41.0% to 54.9%] in Europe HIC and 33.7% [31.6% to 36.0%] in Americas HIC. In 2021 Quarter Three (July to September), median seroprevalence to cumulative incidence ratios ranged from around 2:1 in the Americas and Europe HICs to over 100:1 in Africa (LMICs). Children 0 to 9 years and adults 60+ were at lower risk of seropositivity than adults 20 to 29 (p < 0.001 and p = 0.005, respectively). In a multivariable model using prevaccination data, stringent public health and social measures were associated with lower seroprevalence (p = 0.02). The main limitations of our methodology include that some estimates were driven by certain countries or populations being overrepresented. In this study, we observed that global seroprevalence has risen considerably over time and with regional variation; however, over one-third of the global population are seronegative to the SARS-CoV-2 virus. Our estimates of infections based on seroprevalence far exceed reported Coronavirus Disease 2019 (COVID-19) cases. Quality and standardized seroprevalence studies are essential to inform COVID-19 response, particularly in resource-limited regions.